Post Kidney Transplant: Bone Mineral Disease

Abstract

Bone disease is a major cause of morbidity after kidney transplantation. Post-transplant bone disease results from a combination of renal osteodystrophy related to preexisting chronic kidney disease-mineral and bone disorder (CKD-MBD) and the development or progression of osteoporosis. Early studies after kidney transplant revealed a rapid decrease in bone mineral density (BMD) of 4-10% in the first 6 months after transplant. The incidence of fractures in kidney transplant recipients is four times higher than that of the general population. Measurements of BMD and fracture risk assessment with the online Fracture Risk Assessment Tool (FRAX) are useful tools in identifying and monitoring bone disease. A bone biopsy is the gold standard for the diagnosis of bone disease, however, they are rarely performed. Lifestyle modifications such as weight-bearing exercises, smoking cessation, increased sun exposure, and optimization of diet, along with reducing glucocorticoid exposure can help to minimize bone loss. Pharmacologic agents include calcium, vitamin D, calcimimetics, antiresorptive agents, and hormone therapy. Supplementation with calcium and vitamin D should be part of standard management to prevent bone loss after a kidney transplant, however are generally not sufficient in patients taking high-dose glucocorticoids and additional pharmacologic therapy is often required.